Pioneer SX 780 Receiver compatibility with RSL 4200 studio speakers

I just purchased these speakers for my son and would like to know what db sensitivity is.
I know that the speakers are 4 OHM ....will the Pioneer match with speakers.
Any pioneer receiver or amplifier will drive them to reasonable levels
It will drive the RSL's just fine, but at 4 ohms, don't connect B speakers and run them at the same time as the RSL's.......  That will strain the amp too much... and it's a very old amp.